HALL OF A PROBLEM? Attendance at the National Baseball Hall of Fame in Cooperstown may be down this year if no living players are selected for induction as a result of the steroid controversy. Photo: Anthony J. Causi

At last, a date.

The Yankees announced late yesterday afternoon the long-awaited surgery on Alex Rodriguez’s left hip will be performed Jan. 16.

The team made the announcement during a conference call with Dr. Bryan Kelly, who will perform the two-hour, arthroscopic procedure at the Hospital for Special Surgery in Manhattan. During the 45-minute call, Kelly reiterated many of the same points he made to Joel Sherman in an exclusive interview published in yesterday’s Post.

The 37-year-old third baseman, who suffered through a humiliating postseason which saw him pinch hit for and, ultimately, benched, has spent the past few months strengthening the muscles around the hip joint which, Kelly said, will speed up his post-operative rehab.

“Operating earlier actually will frequently result in a more prolonged recovery afterward because it takes longer for the muscles to respond and recover from the surgery,” he said. “The ultimate issue is … what is the best strategy to get somebody back to full function the fastest.’’

Kelly said following the surgery there will be a period of “protective weight bearing” for Rodriguez that could last between 10 days and four weeks in which he will have to rely on his right hip, which was surgically repaired in 2009.

“We want to minimize the amount of time he has to spend relying on his right hip,” Kelly said. “The last thing we want to do is compromise the right hip because we prematurely operated on the left side. He has a lot of complicating factors. … I’m concerned about his right hip and how it will respond.’’

Kelly again said A-Rod’s hip injury was not caused by performance-enhancing drugs, but rather by a combination of genetics, the structure of Rodriguez’s hip socket and the mechanical force his hip joint has been subjected to.

“This is not a drug-induced problem. It is a developmental problem,’’ said Kelly, who added he performs approximately 500 hip surgeries annually. “This has nothing to do with performance-enhancing drugs.’’

Kelly also repeated he expects Rodriguez to return to the Yankees’ lineup after the All-Star break.

“That’s what we’re hoping for him given all the variables,” he said. “It’d be great if he returns faster. There’s a possibility it will take longer. … That’s the best estimate for his hip at this time, but it’s subject to change.”